Collimated protons accelerated from an overdense gas jet irradiated by a 1 µm wavelength high-intensity short-pulse laser
Chen, S.N., M. Vranic, T. Gangolf, E. Boella, P. Antici, M. Bailly-Grandvaux, P. Loiseau, H. Pépin, G. Revet, J.J. Santos, A.M. Schroer, M. Starodubtsev, O. Willi, L.O. Silva, E. d’Humières & J. Fuchs